There are currently plugs marketed by other companies to perform both functions, channeling and plugging, but with different drawbacks that are resolved by these plugs.
Firstly, the equivalent pitch diameter of plugs marketed up until now is ¼″ (13.7 mm.) whereas those herein developed have a pitch diameter of 1″ (33 mm.)
The marketed plugs are mounted in several sub-assemblies, whereas the device of the invention is a single part, i.e., in a single assembly.